1. Field of the Invention
The invention relates generally to power door loops that provide electrical connection between a pivoting door and a wall and more particularly to a power door loop having a circular snap-in housing with an integral wire protection sleeve.
2. Description of the Prior Art
Door loops are well known for transmitting electricity from a wall to a pivoting door. Such door loops commonly transmit power or signals through conductive wires enclosed and shielded in a flexible armored cable. The cable with the enclosed wires is then looped between the wall and the pivoting door in such a way that the loop accommodates the change in distance and direction between points of attachment on the wall and the door when the door is opened and closed. The ends of the cable terminate in housings. In order to install the door loop, holes are made in the surface layers of the wall or jamb and the door for routing or fishing the wires to their destinations. The wires are passed into the holes and then the housings are fixed in place with fastenings so that the housings cover the holes. A potential cause of failure in such door loops is that the wires may chafe against the lip of the hole. Another potential cause of failure is that excessive flexing may cause the cable to break, especially where there are sharp bends in the cable. For best reliability it is desirable to eliminate sharp bends and minimize flexing of the cable as the door is opened and closed. It is generally desirable for the cable to make a broad loop that is as nearly as possible in a plane that is parallel to the door in both open and closed positions. Difficulties with the installation in such door loops are frequently encountered in finding places on the wall and door where there is enough surface space for the housing and the housing can be oriented so that the cable lead into the housing does not have a sharp bend. Furthermore, the appearance of the installation can appear haphazard unless the sides of the housing align with the edges of the jamb or door. Unfortunately, in some installations the desire for a pleasing appearance conflicts with a requirement for minimizing bending. Even neglecting appearance, the installation of existing door loops requires a high level of skill and is relatively time consuming for planning locations of the fastenings so that the housings are correctly oriented before fixing the housings in place. There is a need for a door loop that is improved by being more reliable and easier to install.